The present invention relates generally to the field of optical systems employed in the diagnosis and treatment of tissue, and, more particularly, to the use of contact devices in the spectroscopic characterization of tissue.
Traditional methods of diagnosing tissue within the human body have employed invasive and time consuming techniques such as biopsy procedures to provide accurate diagnosis, and non-invasive techniques such as radiological or magnetic resonance imaging to provide less detailed but useful information as to the condition of tissue. Biopsies involve the removal of tissue from the region of interest where the sample can be subjected to detailed diagnostic, histologic or biochemical study to determine the nature and extent of disease.
An alternative to tissue biopsy is the use of spectroscopy as a diagnostic tool. This type of procedure has been developed in conjunction with the use of stains or dyes which provide or enhance spectroscopic features associated with certain types or stages of disease.
However the in vivo applications of these techniques are limited due to the difficulties and the expense in delivering the diagnostic marker to the site or region of interest and due to the limited understanding of the spectral information produced.
When tissue is irradiated, a number of mechanisms occur including fluorescence, elastic and inelastic scattering, absorption and reflection of light. These mechanisms produce complicated spectra from which the diagnostically useful information can be extracted. These spectra, when compared with the spectra of normal tissue, can indicate the nature and extent of diseases.